YEREVAN -- Armenian President Serzh Sarkisian has increased his criticism of Turkey's preconditions for normalizing Turkish-Armenian relations, saying they run counter to bilateral agreements made during year-long negotiations, RFE/RL’s Armenian Service reports.

Sarkisian said at a festival for young members of the Armenian diaspora on July 30 at Lake Sevan that he is frustrated by recent developments in the Turkish-Armenian dialogue.

"We Armenians are an independent nation, and it is inadmissible to talk to us in the language of preconditions," he said. "Any tough step brings about countersteps."

Sarkisian did not elaborate on the warning but threatened last week to skip the October soccer match between Armenia and Turkey in Istanbul if Turkey does not take steps toward opening the border between the two countries.

In recent months, Prime Minister Recep Tayyip Erdogan and other Turkish leaders have said that the Turkish-Armenian border will remain closed as long as the conflict with Azerbaijan over the Nagorno-Karabakh region remains unresolved.

Echoing Sarkisian's criticism, 82 members of the U.S. House of Representatives sent a joint letter to President Barack Obama on July 30 expressing concern about "Turkish backpedaling" on the still unpublicized "road map" deal that was announced on April 22.